What is the most deadly disease a person can get?
What is the most common and rare disease people
can get? How will science help us in the future
and why do we learn about science?

Question Date: 2002-05-08

Answer 1:

Well, it depends on how you define "deadliest."
If you mean what kills the most people, the
deadliest disease in the US is nicotine
addiction. Smoking kills more people than any
other disease in America by causing, or helping to
cause, heart disease, high blood pressure,
several types of cancer, and a variety of
breathing diseases.

Worldwide, tuberculosis or malaria kill
the most people per year. About 300-500 million
people get malaria every year, and about 1% of
them die. (1% seems pretty small doesn't it?
But how many people is that?) We don't hear
about it a lot in the United States because it is
mostly found in tropical areas. Malaria is caused
by a microscopic parasite. It lives inside red
blood cells (RBCs carry oxygen). Mosquitoes carry
the parasite from one victim to another. Victims
of the disease suffer from severe cycles of fevers
and chills.

Let me use this as an example of one of the
ways science helps people. By using the
scientific process, people discovered the cause,
treatment, and prevention of malaria . In
fact, the word "malaria" means "bad air"
because people used to think that bad air caused
the disease. If you don't know what causes a
disease, it's hard to stop yourself from getting
it. Now that we know, we have medicines to stop
people from getting malaria, medicines to cure it,
and ways to avoid getting bitten, like mosquito
netting, repellent, and poison. Communities can
also take simple steps like getting rid of trash
that holds water (old tires, open cans, etc.)
because mosquitoes lay their eggs in them.
Malaria is still common because many people cannot
afford the drugs or prevention programs. This is
where science alone is not enough to solve the
problem. What would help us protect more
people from malaria?

The most common disease listed by the World
Health Organization is diarrhea. There are
about 4 billion cases a year. (How many people
are there in the world?) This doesn't really
count as one disease because diarrhea can have a
lot of causes. About 2 billion people have
tuberculosis.